Efeito da radiação ultravioleta de banda "C" sobre queratinócitos humanos e avaliação de materiais com potencial protetor para a saúde cutânea

Abstract

Ultraviolet (UV) radiation is an established method in the literature, inactivating microorganisms by damaging their nucleic acids. Radiation exposure can affect not only the intracellular material of the microorganism but also a set of cells specific to exposed individuals. In response to the COVID-19 pandemic, there has been an increase in the use of UV-C radiation devices. However, the increased use of these devices for surface disinfection increases the risks of human exposure to this radiation. Thus, it is important to assess the effects of this exposure on human cells, such as keratinocytes, to ensure the effectiveness and safety of using these devices. Therefore, the present study aimed to evaluate the effects of exposure to UV-C radiation (254 nm) on a lineage of human non-tumoral keratinocytes (HaCaT) at different exposure times and the protection provided by different materials. To this end, keratinocytes were exposed for different periods (10, 60, or 300s) to UVC radiation (±16 mW/cm², 254 nm) and evaluated at 1, 6, 24, or 72 hours after exposure, with or without the presence of protective materials. The parameters evaluated were: cell viability, morphological analysis by optical microscopy in cells stained with crystal violet, staining with fluorescent dyes to assess cell death by apoptosis or necrosis (acridine orange and propidium iodide staining - AO/PI), reactive oxygen species production assay, and clonogenic assay. Exposure to radiation for 10 seconds resulted in progressive damage affecting various parameters, such as cell viability, with a notable decrease in viable cells at the different time intervals evaluated. Additionally, morphological changes and cell density were observed, as well as an increase in dead cells, evidencing atypical characteristics compared to unexposed cells. A significant increase in reactive species production was also observed, indicating radiation-induced oxidative stress. Notably, the use of protective materials, such as latex and nitrile, conferred significant protection to the cells, maintaining their viability and morphology similar to that of the unexposed group. These results indicate the deleterious effects of UV-C radiation on cells, corroborating with the literature, and suggest that the use of protective materials may help mitigate these effects.